We have obtained over 30 acapsular mutants of C. neoformans by plating mutagenized cells and picking dry colonies. We have characterized these mutants phenotypically by India ink smears, electron microscopy, immunofluorescence and partition in a charged 2-phase system. We now plan to characterize them genetically by crossing all possible pairs of mutants and determining linkage relationships. By this method we will be able to estimate the number of genetic loci involved in biosynthesis of the capsule and to assign mutants to each locus.